I realize I'm just some rando on the Internet, but I'm begging you please don't introduce Yet Another CI Job Specification ™
I'm sure you have your favorites, or maybe you hate them all equally and can just have a dartboard but (leaving aside the obvious xkcd joke) unless you're going to then publish a JSON Schema and/or VSCode and/or IJ plugin to edit whatever mysterious new thing you devise, it's going to be yet another thing where learning it only helps the learner with the Radicle ecosystem, and cannot leverage the existing knowledge
It doesn't even have to be yaml or json; there are quite a few projects which take the old(?) Jenkinsfile approach of having an actual programming language, some of them are even statically typed
I also do recognize the risk to your project of trying to fold in "someone else's" specification, but surely your innovation tokens are better spent on marketing and scm innovations, and not "how hard can it be" to cook a fresh CI job spec
I likely would have already written a much shorter comment to this effect, but having spent the past day slamming my face against the tire fire of AWS CodeBuild, the pain is very fresh from having to endure them thinking they're some awesome jokers who are going to revolutionize the CI space